PC boots as normal, load a program/game/whatever, everything is fine for 5 minutes, then crashes (mouse freezes, 'jarring' sound constant).
Boots up into 'Scan for errors' - halfway through it crashes again.
Sometimes crashes after memory test, sometimes during boot.
Then everything's OK - Stable for indefinite period. Shuts down OK.
Same problem next time I turn it on.
Could this be a hardware error - like my motherboard, my hard drive, or its controller? I don't see as how it could be a software error if it crashes just after the memory test!
This PC is now 3 years old (2002) and has seen a fair bit of use but not like 24/7.
Registry is clean, Ad's are wiped, Scandisk & defragged recently.